With the recent heat wave and Memorial Day around the corner, we must remember to protect our skin against sun damage.

One blistering sunburn in childhood or adolescence doubles a person's chances of developing melanoma (the most serious form of skin cancer). Melanoma risk also doubles if he or she has had five or more sunburns at any age. Since more than 90 percent of all skin cancers are caused by sun exposure, sunscreens are a key weapon in the arsenal against the disease.

A sunscreen’s efficacy is measured by its sun protection factor, or SPF. This number indicates how long it will take for sun rays to redden the skin when using a sunscreen compared to how long it will take to redden the skin without the product. For example, someone using a sunscreen with an SPF of 15 will take 15 times longer to redden than without the sunscreen.

Ultraviolet radiation (especially UVA and UVB) can travel through car and home windows, where it can contribute to the daily accumulation of sun exposure that can lead to skin damage and skin cancer. An SPF 15 sunscreen blocks 93 percent of the sun’s UVB rays; SPF 30 protects against 97 percent; and SPF 50, 98 percent. UV-blocking car window shades can also protect you against this exposure.

With the dog days of summer approaching, remember to be mindful of the sun’s harmful effects and take the following precautions.

1. Seek the shade, especially between 10 a.m. to 4 p.m.
2. Do not burn.
3. Avoid tanning and UV tanning booths.
4. Cover up with clothing, including a broad-brimmed hat and UV-blocking   sunglasses.
5. Use a sunscreen with an SPF of 15 or higher every day.
6. Apply 1 ounce (2 tablespoons) of sunscreen to your entire body 30 minutes before going outside. Re-apply every two hours, or immediately after swimming or excessive sweating.
7. Keep newborns out of the sun. Sunscreens should be used on babies over the age of 6 months.
8. Examine your skin head-to-toe every month.
9. See your physician every year for a professional skin exam.